Factors associated with adherence to an end-of-study biopsy: Lessons from the Prostate Cancer Prevention Trial (SWOG-Coordinated Intergroup Study S9217) - Abstract

BACKGROUND: The Prostate Cancer Prevention Trial (PCPT) was a 7-year randomized, double-blind, placebo-controlled trial of the efficacy of finasteride for the prevention of prostate cancer with a primary outcome of histologically determined prevalence of prostate cancer at the end of 7 years.

METHODS: A systematic modeling process using logistic regression identified factors available at year 6 that are associated with end-of-study (EOS) biopsy adherence at year 7, stratified by whether participants were ever prompted for a prostate biopsy by year 6. Final models were evaluated for discrimination. At year 6, 13,590 men were available for analysis.

RESULTS: Participants were more likely to have the EOS biopsy if they were adherent to study visit schedules and procedures and/or were in good health (P < 0.01). Participants at larger sites and/or sites that received retention and adherence grants were also more likely to have the EOS biopsy (P < 0.05).

CONCLUSIONS: Our results show good adherence to study requirements 1 year before the EOS biopsy was associated with greater odds that a participant would comply with the invasive EOS requirement.

IMPACT: Monitoring adherence behaviors may identify participants at risk of nonadherence to more demanding study end points. Such information could help frame adherence intervention strategies in future trials.

Written by:
Gritz ER, Arnold KB, Moinpour CM, Burton-Chase AM, Tangen CM, Probstfield JF, See WA, Lieber MM, Caggiano V, Moody-Thomas S, Szczepanek C, Ryan A, Carlin S, Hill S, Goodman PJ, Padberg RM, Minasian LM, Meyskens FL, Thompson IM Jr.   Are you the author?
Institution(s): See publishing journal.

Reference: Cancer Epidemiol Biomarkers Prev. 2014 Aug;23(8):1638-48.
doi: 10.1158/1055-9965.EPI-14-0202

PubMed Abstract
PMID: 25028457

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